Distillation of water is a process in which various soluble materials such as salt, contaminants etc. are eliminated from water containing these materials, leaving clean, usually drinkable water. One known method for achieving such distillation relies on water evaporation, much like salt and scale being accumulated on the bottom of an electric kettle after water has evaporated. In this process during evaporation of the water, soluble materials that are not volatile remain in a solid state residue, usually in the form of salt and scale, and are disposed of. The vapor can then be condensed back into a state of liquid, resulting in contaminant free water.
U.S. Pat. No. 3,868,308 to the applicant discloses a multiple effect evaporator system, comprising a housing and a plurality of effects connected in a series to one another, each effect having a plurality of bundles of tubes. The system is built such that high temperature steam is introduced into the tubes of the first effect, while non-distilled water is sprayed against the outside of the tubes, causing the vapor in the tube to condense while evaporating a part of the non-distilled water. The remainder of steam from the tubes of the first effect, along with the evaporated water outside the tubes enters the tubes of the adjacent downstream effect, while the remainder of the non-distilled water which has not evaporated, is accumulated at the bottom of the effect housing in the form of a concentrate and is moved to be sprayed against the outside of the tubes of the adjacent upstream effect and so on and so forth.
Once water has completed its passage through all the effects of the evaporator system, the process yields distilled water on the downstream end of the evaporator and a warm concentrate in the form of a highly concentrated water solution of soluble materials on the upstream end.